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Dai Y, Huang D, Zhao W, Wei J. A comparative study of elective nodal irradiation and involved field irradiation in elderly patients with advanced esophageal cancer. Front Oncol 2023; 13:1323908. [PMID: 38173832 PMCID: PMC10763665 DOI: 10.3389/fonc.2023.1323908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 11/21/2023] [Indexed: 01/05/2024] Open
Abstract
Objective This comparative study aimed to explore the feasibility of involved field irradiation (IFI) in the radiotherapy of elderly patients with advanced esophageal cancer, compared with elective nodal irradiation (ENI). Methods A total of 245 elderly patients (age ≥70 years) with advanced esophageal cancer, who received radiotherapy in our department from January 2014 to December 2020, were divided into the ENI group (n=111) and the IFI group (n=134). Clinical efficacy, toxicities, survival rates, treatment failures, and multifactorial survival analyses were conducted for both groups. Results The ENI group and the IFI group showed no significant differences in terms of short-term efficacy (91.9% vs 91.0%, P=0.814), 1-year overall survival (OS) (81.1% vs 74.6%, P=0.228), 2-year OS (22.5% vs 25.4%, P= 0.603), 1-year progression-free survival (PFS) (56.8% vs 51.5%, P= 0.198), 2-year PFS (8.1% vs 9.0%, P=0.814), regional failures (38.7% vs 31.3%, P=0.226), and distant metastasis (21.6% vs 14.9%, P=0.174). The median overall survival (OS) was 19 months in the ENI group and 18 months in the IFI group (Log-rankχ 2 = 0.012, P=0.913). The median progression-free survival (PFS) was 13 months in the ENI group and 11 months in the IFI group (Log-rankχ 2 = 1.834, P=0.176). There were no significant statistical differences in both OS and PFS (P>0.05). The incidence of grade ≥3 radiation pneumonia and grade ≥3 radiation esophagitis in the IFI group was 8.2% and 11.2%, respectively, which were significantly lower than those in the ENI group (17.1%, P=0.034; 21.6%, P=0.026). Univariate analysis revealed that age, gender, T stage, N stage, and synchronous chemotherapy were factors affecting prognosis. Multivariate analysis showed that age, gender, T stage, and synchronous chemotherapy were independent prognostic factors, with hazard ratios of 1.227, 1.466, 2.441, and 2.714, and P values of <0.001, 0.006, <0.001, and<0.001, respectively. Conclusion IFI is a suitable choice for elderly patients with advanced esophageal cancer, as it yields similar efficacy to ENI while reducing toxicities. Age, gender, T stage, and synchronous chemotherapy are independent prognostic factors for elderly patients with esophageal cancer.
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Affiliation(s)
| | | | | | - Jie Wei
- Department of Oncology, The Affiliated Chuzhou Hospital of Anhui Medical University (The First People’s Hospital of Chuzhou), Chuzhou, Anhui, China
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Peschel DP, Düsberg M, Peeken JC, Kaiser JC, Borm KJ, Sommer K, Combs SE, Münch S. Incidental nodal irradiation in patients with esophageal cancer undergoing (chemo)radiation with 3D-CRT or VMAT. Sci Rep 2022; 12:22333. [PMID: 36567356 PMCID: PMC9790887 DOI: 10.1038/s41598-022-26641-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 12/19/2022] [Indexed: 12/26/2022] Open
Abstract
The extent of elective nodal irradiation (ENI) in patients undergoing definitive chemoradiotherapy (dCRT) for esophageal squamous cell carcinoma (ESCC) remains unclear. The aim of this dosimetric study was to evaluate the extent of incidental nodal irradiation using modern radiation techniques. A planning target volume (PTV) was generated for 30 patients with node-negative esophageal carcinoma (13 cervical/upper third, 7 middle third, 10 lower third/abdomen). Thereby, no elective nodal irradiation (ENI) was intended. Both three-dimensional conformal radiotherapy (3D-CRT) and volumetric-modulated arc therapy (VMAT) treatment plans (50 Gy in 25 fractions) were calculated for all patients. Fifteen nodal stations were contoured according to the definitions of the AJCC and investigated in regard to dosimetric parameters. Compared to 3D-CRT, VMAT was associated with lower dose distribution to the organs at risk (lower Dmean, V20 and V30 for the lungs and lower Dmean and V30 for the heart). For both techniques, the median Dmean surpassed 40 Gy in 12 of 15 (80%) nodal stations. However, VMAT resulted in significantly lower Dmeans and equivalent uniform doses (EUD) compared to 3D-CRT for eight nodal stations (1L, 2L, 2R, 4L, 7, 8L, 10L, 15), while differences did not reach significance for seven nodal station (1R, 4R, 8U, 8M, 10R, 16). For dCRT of ESCC, the use of VMAT was associated with significantly lower median (incidental) doses to eight of 15 regional lymph node areas compared to 3D-CRT. However, given the small absolute differences, these differences probably do not impair (regional) tumor control rates.
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Affiliation(s)
- David Paul Peschel
- Department of Radiation Oncology, Klinikum Rechts Der Isar, Technical University Munich (TUM), Ismaninger Str. 22, 81675, Munich, Germany
| | - Mathias Düsberg
- Department of Radiation Oncology, Klinikum Rechts Der Isar, Technical University Munich (TUM), Ismaninger Str. 22, 81675, Munich, Germany
| | - Jan C Peeken
- Department of Radiation Oncology, Klinikum Rechts Der Isar, Technical University Munich (TUM), Ismaninger Str. 22, 81675, Munich, Germany
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München (HMGU), Ingolstädter Landstraße 1, 85764, Oberschleißheim, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany
| | - Jan Christian Kaiser
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München (HMGU), Ingolstädter Landstraße 1, 85764, Oberschleißheim, Germany
| | - Kai Joachim Borm
- Department of Radiation Oncology, Klinikum Rechts Der Isar, Technical University Munich (TUM), Ismaninger Str. 22, 81675, Munich, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany
| | - Katharina Sommer
- Department of Radiation Oncology, Klinikum Rechts Der Isar, Technical University Munich (TUM), Ismaninger Str. 22, 81675, Munich, Germany
| | - Stephanie E Combs
- Department of Radiation Oncology, Klinikum Rechts Der Isar, Technical University Munich (TUM), Ismaninger Str. 22, 81675, Munich, Germany
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München (HMGU), Ingolstädter Landstraße 1, 85764, Oberschleißheim, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany
| | - Stefan Münch
- Department of Radiation Oncology, Klinikum Rechts Der Isar, Technical University Munich (TUM), Ismaninger Str. 22, 81675, Munich, Germany.
- German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany.
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Wang H, Song C, Zhao X, Deng W, Shen W. The role of involved field irradiation versus elective nodal irradiation in definitive radiotherapy or chemoradiotherapy for esophageal cancer- a systematic review and meta-analysis. Front Oncol 2022; 12:1034656. [PMID: 36408184 PMCID: PMC9666894 DOI: 10.3389/fonc.2022.1034656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/17/2022] [Indexed: 01/25/2023] Open
Abstract
OBJECTIVE This study aimed to analyze whether involved field irradiation (IFI) is associated with improving survival outcomes and reducing adverse events compared with elective nodal irradiation (ENI) in patients of esophageal cancer who underwent definitive radiotherapy or chemoradiotherapy. SUMMARY BACKGROUND DATA Radiotherapy plays an important role for not surgery patients. However, the role of radiation target size is still uncertain. METHODS We searched Web of Science, Embase, PubMed, and Cochrane Central for English and non-English publications comparing esophageal cancer patients who received radiotherapy with IFI with those with ENI. Primary outcomes included overall survival (OS) and adverse events related to radiotherapy. The risk of bias was assessed using the Cochrane Risk of Bias tool for randomized studies and the Newcastle-Ottawa Scale and Agency for Healthcare Research and Quality Standard for non-randomized studies. We evaluated the certainty of evidence by Grading of Recommendations, Assessment, Development, and Evaluation. RESULTS Totally, 23 studies with 4120 patients were included. IFI group demonstrated significant improvement in the OS rates at 5 years, but not at 1, 2, and 3 years, compared with the ENI group (pooled Risk Ratio [RR], 0.78; 95% confidence interval [CI], 0.68-0.90; P = 0.0004; high certainty). In addition, IFI demonstrated a significant decrease in the incidence of grade ≥2 acute esophagitis (AE) (pooled RR, 0.79; 95% CI, 0.69-0.90; P = 0.0005; high certainty) and grade ≥3 AE (pooled RR, 0.51; 95% CI, 0.38-0.69; P < 0.00001; high certainty) compared with ENI, but not in the incidence of grades ≥3 acute pneumonia, late esophagitis, and late pneumonia. CONCLUSIONS Compared to ENI, IFI demonstrated significant improvement in OS at 5 years. The addition of intensity-modulated radiotherapy (IMRT) to IFI increased the 5-year OS; however, similar results were not observed with the addition of three-dimensional conformal radiotherapy to IFI and ENI. Furthermore, IFI demonstrated a significant decrease in grade ≥2 and grade ≥3 AE, while IMRT demonstrated no difference in the incidence of grade ≥3 AE. IFI and ENI do not differ in the incidence of grades ≥3 acute pneumonia, late esophagitis, and late pneumonia.
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Wang S, Ji B, Li C, Han W, Wang X, Zhou Z, Chen D, Feng Q, Liang J, Lv J, Bi N, Deng L, Wang W, Zhang T, Xiao Z. Factors affecting the completion of concurrent chemotherapy and impact of non-completion on survival in locally advanced esophageal squamous cell carcinoma. Esophagus 2022; 19:717-725. [PMID: 35760946 DOI: 10.1007/s10388-022-00930-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/30/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND To investigate whether completion of concurrent chemotherapy (CCT) improves overall survival (OS) of patients with locally advanced esophageal squamous cell carcinoma (ESCC), and to identify predictors of non-completion of CCT. METHODS Data of ESCC patients treated with definitive concurrent chemoradiotherapy from January 2012 to December 2017 were retrospectively analyzed. CCT completion was defined as receiving recommended cycles with at most 25% dose reduction. Propensity score matching (PSM) analysis was applied to adjust unbalanced covariates between groups. Multivariate logistic regression model was used to identify factors affecting CCT completion. RESULTS Of the 487 patients in the study, 194 patients (39.8%) had completed CCT. The majority (90.7%) had stage III-IV disease. Three-year OS rate was significantly higher in the completion group than non-completion group (35.4% vs. 30.3%; p = 0.025). Multivariate Cox analysis showed CCT completion was independently associated with longer OS (p = 0.005). The independent risk factors for CCT non-completion were weekly CCT regimen [odds ratio (OR) = 4.35, 95% CI 2.26-8.37; p < 0.001], clinical target volume (CTV)-elective nodal irradiation (ENI) (OR = 3.86, 95% CI 2.41-6.18; p < 0.001), planning target volume (PTV)/50 cm3 (OR = 1.09, 95% CI 1.02-1.16; p = 0.017), age (OR = 1.04, 95% CI 1.01-1.07, p = 0.011), and tumor in middle/lower esophagus (OR = 1.59, 95% CI 1.05-2.43, p = 0.030). CONCLUSION CCT completion can provide superior OS for ESCC patients treated with definitive CCRT. Weekly CCT regimen, CTV-ENI, PTV, older age, and tumor location are independent predictors of non-completion of CCT.
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Affiliation(s)
- Shijia Wang
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Baoyan Ji
- Department of Oncology, Qinghai Provincial People's Hospital, Xining, 810000, Qinghai, People's Republic of China
| | - Chen Li
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Weiming Han
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Xin Wang
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Zongmei Zhou
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Dongfu Chen
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Qinfu Feng
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Jun Liang
- Department of Radiation Oncology, Cancer Hospital Chinese Academy of Medical Sciences, Shenzhen Center, Shenzhen, 518000, Guangdong, People's Republic of China
| | - Jima Lv
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Nan Bi
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Lei Deng
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Wenqing Wang
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Tao Zhang
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Zefen Xiao
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, 100021, People's Republic of China.
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Zhu H, Lu X, Jiang J, Lu J, Sun X, Zuo Y. Radiotherapy Combined With Concurrent Nedaplatin-Based Chemotherapy for Stage II-III Esophageal Squamous Cell Carcinoma. Dose Response 2022; 20:15593258221076720. [PMID: 35273471 PMCID: PMC8902195 DOI: 10.1177/15593258221076720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Objective This study was conducted to explore the appropriate radical radiation dose in concurrent chemoradiotherapy (CCRT) for patients with inoperable stage II-III esophageal squamous cell carcinoma (ESCC). Methods This retrospective study included patients with esophageal cancer (EC) from the database of patients treated at the Affiliated Zhangjiagang Hospital of Soochow University (1/2015-12/2019). Overall survival (OS), progression-free survival (PFS), objective remission rate (ORR), first failure pattern, and toxicities were collected. Results 112 patients treated with intensity-modulated radiation therapy (IMRT) combined with concurrent chemotherapy of nedaplatin-based regimens were included. Fifty-eight (51.8%) and 54 (48.2%) patients received 60 (HD) and 50.4 (LD) Gy of radiotherapy, respectively. The HD group showed superior OS and a trend for longer PFS compared with the LD group (median OS: 25.5 vs 17.5 months, P = .021; median PFS: 14.0 vs 10.5 months, P = .076). There were more patients with a complete remission (CR) in the HD group than in the LD group (P=.016). The treatment-related toxicities were generally acceptable, but HD radiotherapy would increase the incidence of grade ≥3 late radiotoxicity (22.4% vs 5.6%, P = .011). Conclusion In nedaplatin-based CCRT for stage II-III ESCC, the radiotherapy dose of 60 Gy achieved a better prognosis. Strengths and limitations of this study A comparative study of 50.4 Gy and 60 Gy was conducted to evaluate whether 50.4 Gy can be used as a radical radiotherapy dose for inoperable stage II-III esophageal squamous cell carcinoma from a real-world perspective.The highly consistent selection criteria in our study make analysis results highly reliable and scientific.The existing research results support that nedaplatin can be used in concurrent chemoradiotherapy for esophageal squamous cell carcinoma, and this study focuses on the discovery of a better nedaplatin-based combination regimen.The findings of this study are limited to a single-center study with a non-large sample size.Inevitably, recall bias may exist in this retrospective study.Surgery was not involved in the follow-up treatment after concurrent chemoradiotherapy, which may worsen the prognosis of some patients.
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Affiliation(s)
- Huiping Zhu
- Department of Oncology, the Affiliated Zhangjiagang Hospital
of Soochow University, Suzhou, China
| | - Xiaoling Lu
- Department of Oncology, the Affiliated Zhangjiagang Hospital
of Soochow University, Suzhou, China
| | - Jian Jiang
- Department of Oncology, the Affiliated Zhangjiagang Hospital
of Soochow University, Suzhou, China
| | - Jingfeng Lu
- Department of Oncology, the Affiliated Zhangjiagang Hospital
of Soochow University, Suzhou, China
| | - Xinchen Sun
- Department of Radiation Oncology, the First Affiliated Hospital of
Nanjing Medical University, Nanjing, China
| | - Yun Zuo
- Department of Oncology, the Affiliated Zhangjiagang Hospital
of Soochow University, Suzhou, China
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Chemoradiotherapy with extended nodal irradiation and/or erlotinib in locally advanced oesophageal squamous cell cancer: long-term update of a randomised phase 3 trial. Br J Cancer 2020; 123:1616-1624. [PMID: 32958820 PMCID: PMC7686329 DOI: 10.1038/s41416-020-01054-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 07/23/2020] [Accepted: 08/26/2020] [Indexed: 11/08/2022] Open
Abstract
Background To report the long-term outcomes of a phase III trial designed to test two hypotheses: (1) elective nodal irradiation (ENI) is superior to conventional field irradiation (CFI), and (2) chemoradiotherapy plus erlotinib is superior to chemoradiotherapy in locally advanced oesophageal squamous cell cancer (ESCC). Methods Patients with locally advanced ESCC were randomly assigned (1:1:1:1 ratio) to one of the four groups: A: radiotherapy adoption of ENI with two cycles of concurrent TP chemotherapy (paclitaxel and cisplatin) plus erlotinib; B: radiotherapy adoption of ENI with two cycles of concurrent TP; C: radiotherapy adoption of CFI with two cycles of concurrent TP plus erlotinib and D: radiotherapy adoption of CFI with two cycles of concurrent TP. A total of 60 Gy of radiation doses was delivered over 30 fractions. We explored the impact of epidermal growth factor receptor (EGFR) expression on the efficacy of erlotinib plus chemoradiotherapy. Results A total of 352 patients (88 assigned to each treatment group) were enrolled. The 5-year survival rates were 44.9%, 34.8%, 33.8% and 19.6% in groups A, B, C and D, respectively (P = 0.013). ENI significantly improved OS compared with standard CFI (median, 38.5 vs 22.6 months; HR, 0.74; P = 0.018). The addition of erlotinib significantly improved OS (median, 39.4 vs 27.4 months; HR, 0.75; P = 0.025). Patients with overexpressing EGFR treated with erlotinib had a better OS and PFS than those without erlotinib. Conclusions Concurrent chemoradiotherapy with ENI and/or erlotinib improved long-term survival in locally advanced ESCC. Clinical trial registration Trial registration: NCT00686114.
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Kanayama N, Otozai S, Yoshii T, Toratani M, Ikawa T, Wada K, Hirata T, Morimoto M, Konishi K, Ogawa K, Fujii T, Teshima T. Death unrelated to cancer and death from aspiration pneumonia after definitive radiotherapy for head and neck cancer. Radiother Oncol 2020; 151:266-272. [PMID: 32866561 DOI: 10.1016/j.radonc.2020.08.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 07/21/2020] [Accepted: 08/24/2020] [Indexed: 02/01/2023]
Abstract
BACKGROUND AND PURPOSE The incidence of hypopharyngeal and supraglottic cancer (HSC) is high in Japan. This study aimed to retrospectively identify risk factors for death unrelated to cancer and death from aspiration pneumonia after definitive radiotherapy (RT) for HSC. MATERIALS AND METHODS Overall, 391 patients who began definitive RT for HSC between 2006 and 2014 were identified from the Osaka International Cancer Institute electronic database. Among 391 patients, 33 had a history of surgery for esophageal cancer (EC) and 19 received simultaneous RT for synchronous EC. The cause of death was divided into 3 main categories: "cancer under study," "other malignancy," and "unrelated to cancer." Cox proportional hazard model was used to estimate the hazard ratio (HR). RESULTS The median follow-up for survivors was 8 (range 3.6-14.1) years. At the last follow-up, 202 patients died. Death from "cancer under study," "other malignancy," and "unrelated to cancer" occurred in 92 (45.5%), 55 (27.2%), and 55 (27.2%) patients, respectively. Twelve patients died from aspiration pneumonia. In multivariate analysis for death unrelated to cancer and death from aspiration pneumonia, history of surgery for EC (HR: 3.87, p < 0.001; HR: 6.84, p = 0.007, respectively) and simultaneous RT for synchronous EC (HR: 3.74, p = 0.006; HR: 16.37, p < 0.001, respectively) were significant risk factors. CONCLUSION The laryngeal preservation approach by RT for HSC patients with a history of surgery for EC and simultaneous RT for synchronous EC should be used with caution.
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Affiliation(s)
- Naoyuki Kanayama
- Department of Radiation Oncology, Osaka International Center Institute, Osaka, Japan.
| | - Shinji Otozai
- Department of Head and Neck Surgery, Osaka International Center Institute, Osaka, Japan
| | - Tadashi Yoshii
- Department of Head and Neck Surgery, Osaka International Center Institute, Osaka, Japan
| | - Masayasu Toratani
- Department of Radiation Oncology, Osaka International Center Institute, Osaka, Japan
| | - Toshiki Ikawa
- Department of Radiation Oncology, Osaka International Center Institute, Osaka, Japan
| | - Kentaro Wada
- Department of Radiation Oncology, Osaka International Center Institute, Osaka, Japan
| | - Takero Hirata
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Masahiro Morimoto
- Department of Radiation Oncology, Osaka International Center Institute, Osaka, Japan
| | - Koji Konishi
- Department of Radiation Oncology, Osaka International Center Institute, Osaka, Japan
| | - Kazuhiko Ogawa
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Takashi Fujii
- Department of Head and Neck Surgery, Osaka International Center Institute, Osaka, Japan
| | - Teruki Teshima
- Department of Radiation Oncology, Osaka International Center Institute, Osaka, Japan
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